CAREER: Post-transcriptional regulation of mRNA stability in Mycobacterium smegmatis

这个项目的目标是了解细菌如何适应压力条件，例如缺乏营养或氧气。众所周知，细菌能够改变自己的生理机能，以便在不利的条件下生存，但具体是如何发生的还不清楚。这项工作将探索细菌如何激活某些基因并停止使用其他基因，以节省能量以应对压力。由于细菌在许多方面影响人类的生活--通过塑造我们的环境，影响我们的健康，并成为研究和工业的重要工具--这项研究的结果应该会产生深远的科学影响。此外，该项目将为研究生和本科生提供宝贵的培训机会，他们将直接参与实验室和基于课程的环境中的研究。将通过开发工具和技术，作为让当地高中生及其教师参与实验室实践研究和对研究结果进行计算分析的平台，扩大教育影响。将开发一个教授基因调控的教育模块，并将其传播到为贫困社区服务的高中。转录丰度的调节是细菌应激反应的关键，可以发生在转录点或降解点。转录后调控对mRNA稳定性和功能的贡献尚不清楚，特别是在分枝杆菌中，因为分枝杆菌在RNA代谢方面与更普遍研究的细菌不同。利用污垢分枝杆菌作为模式生物，本项目的目标是(I)确定转录后调控对转录丰度和功能的影响，以响应压力；(Ii)确定在胁迫诱导的生长抑制过程中全局稳定mRNA的机制；以及(Iii)确定分枝杆菌mRNA降解机制的一些中心组成部分的作用和调节。该方法将结合转录学、遗传学、生物化学和建模来测量mRNA的切割和降解，并测试关于这些过程的调节和表型后果的假设。这项工作将产生关于分枝杆菌mRNA稳定性决定因素和转录后调控对应激反应的贡献的基础知识。从长远来看，转录和转录后机制的信息整合有望导致对分枝杆菌在不同环境中如此成功的压力耐受机制的全面理解。

The goal of this project is to understand how bacteria adapt to stressful conditions, such as lack of nutrients or oxygen. Bacteria are known to be able to modify their physiology in order to survive in under adverse conditions, but exactly how this occurs is not well-understood. This work will explore how bacteria activate certain genes and stop using others in order to conserve energy in response to stress. Because bacteria affect human lives in many ways--by shaping our environment, influencing our health, and serving as important tools for research and industry--the results of this study should have far-reaching scientific impacts. In addition, this project will provide valuable training opportunities for graduate and undergraduate students, who will participate directly in the research in both laboratory and course-based settings. Educational impact will be broadened by developing tools and techniques as a platform for involving local high school students and their teachers in hands-on research in the lab and in computational analyses of research results. An educational module for teaching gene regulation will be developed and disseminated to high schools that serve underprivileged communities. Regulation of transcript abundance is critical to bacterial stress response, and can occur at the point of transcription or at the point of degradation. The contribution of post-transcriptional regulation of mRNA stability and function is poorly understood, particularly in mycobacteria, which differ from more commonly studied bacteria with respect to RNA metabolism. Using Mycobacterium smegmatis as a model organism, the objectives of this project are to (i) determine the impact of post-transcriptional regulation on transcript abundance and function in response to stress; (ii) identify mechanisms that globally stabilize mRNA during stress-induced growth inhibition; and (iii) define the roles and regulation of some of the central components of the mycobacterial mRNA degradation machinery. The approach will combine transcriptomics, genetics, biochemistry, and modeling to measure mRNA cleavage and degradation and test hypotheses about the regulation and phenotypic consequences of these processes. This work will generate foundational knowledge about the determinants of mRNA stability in mycobacteria and the contributions of post-transcriptional regulation to stress response. In the longer term, integration of information on transcriptional and post-transcriptional mechanisms is expected to lead to a comprehensive understanding of the stress tolerance mechanisms that render mycobacteria so successful in diverse environments.